Comparative rating, based on power used versus temperature rise achieved in the performance test. The best models rate as 'good'; acceptable models are 'OK'; 'borderline' means mediocre. See our article on how we test electric heaters for details.

40dBA is very quiet, while 60dBA is equivalent to normal conversation; enough to be disruptive when watching TV, for example. Most fans have one fan setting - apart from a few which have 10. We measure on the maximum fan setting.

Our testers check electrical safety, measure surface temperatures, and carry out a tilt test. They also check which heaters continue heating when on their sides, as if they'd been knocked over. They also perform a towel drape test. See our article on how we test electric heaters for details.

Radiant heaters are personal heaters. They radiate heat from a red-hot heating element.

Convection and panel heaters draw cold air over an electric heating element. The warmed air then leaves the heater and rises towards the ceiling, while cooler air moves in to replace it. This includes oil filled column heaters.

Fan heaters are specifically designed to blow hot air; the fan is a key part of the heater design, rather than a booster as on other heater types. Their fans are usually more powerful and can project the hot air a reasonable distance into the room.

Heaters come in all shapes and sizes, but generally conform to type. If you see elements like 'ceramic' or 'micathermic' we've found these aren't guaranteed to give better results than other formats, so tend to fall into the marketing spin category. We list the common forms seen here, such as oil columns, towers, panel heaters, fan heaters and radiant heaters.

Useful for colder climates as it claims to maintain a temperature of about 5°C if the thermostat is left on its lowest setting, avoiding frost/freezing on the heater which could damage it. We don’t test this feature.